138 research outputs found
CLOSED-LOOP CONTROLLED TOTAL INTRA VENOUS ANAESTHESIA
Anaesthesia is important for both surgery and intensive care and intravenous anaesthetics are
widely used to provide rapid onset, stable maintenance, and rapid recovery compared with
inhaled anaesthetics. The aim of the project on which this thesis is based was to investigate a
reliable and safe methodology for delivering total intravenous anaesthesia using closed-loop
control technology and bispectral analysis of human electroencephalogram (EEG) waveform.
In comparison with Target Controlled Infusion (TCI), drug effect is measured during drug
infusion in closed loop anaesthesia (CLAN). This may provide superior safety, better patient
care, and better quality of anaesthesia whilst relieving the clinician of the need to make
recurrent and minor alterations to drug administration.
However, the development of a CLAN system has been hindered by the Jack of a 'gold
standard' for anaesthetic states and difficulties with patient variability in pharmacokinetic and
pharmacodynamic modelling, and a new and generic mathematical model of a closed-loop
anaesthesia system was developed for this investigation. By using this CLAN model,
investigations on pharmacokinetic and pharmacodynamic variability existing in patients were
carried out. A new control strategy that combines a Proportional, Integral, Derivative (PID)
controller, bispectral analysis of EEG waveform and pharmacokinetic/ pharmacodynamic
models was investigated.
Based on the mathematical model, a prototype CLAN system, the first CLAN system capable
of delivering both hypnotics and analgesics simultaneously for total intravenous anaesthesia,
was developed. A Bispectral Index (BIS), derived from power spectral and bispectral analysis
on EEG waveform, is used to measure depth of anaesthesia. A supervision system with built-in
digital signal processing techniques was developed to compensate the non-linear
characteristics inherent in the system while providing a comprehensive protection mechanism
for patient safety. The CLAN system was tested in 78125 virtual patients modelled using
published data. Investigations on intravenous anaesthesia induction and maintenance with the
CLAN system were carried out in various clinical settings on 21 healthy volunteers and 15
patients undergoing surgery. Anaesthesia targets were achieved quickly and well maintained
in all volunteers/patients except for 2 patients with clinically satisfactory anaesthesia quality.Derriford Hospita
Varieties of interaction: from User Experience to Neuroergonomics:On the occasion of the Human Factors and Ergonomics Society Europe Chapter Annual Meeting in Rome, Italy 2017
Proceedings of the HFES European Chapter conferenc
Varieties of interaction: from User Experience to Neuroergonomics:On the occasion of the Human Factors and Ergonomics Society Europe Chapter Annual Meeting in Rome, Italy 2017
Proceedings of the HFES European Chapter conferenc
Hybrid approaches based on computational intelligence and semantic web for distributed situation and context awareness
2011 - 2012The research work focuses on Situation Awareness and Context Awareness topics.
Specifically, Situation Awareness involves being aware of what is happening in the vicinity
to understand how information, events, and one’s own actions will impact goals and objectives,
both immediately and in the near future. Thus, Situation Awareness is especially
important in application domains where the information flow can be quite high and poor
decisions making may lead to serious consequences.
On the other hand Context Awareness is considered a process to support user applications
to adapt interfaces, tailor the set of application-relevant data, increase the precision of
information retrieval, discover services, make the user interaction implicit, or build smart
environments.
Despite being slightly different, Situation and Context Awareness involve common
problems such as: the lack of a support for the acquisition and aggregation of dynamic environmental
information from the field (i.e. sensors, cameras, etc.); the lack of formal approaches
to knowledge representation (i.e. contexts, concepts, relations, situations, etc.)
and processing (reasoning, classification, retrieval, discovery, etc.); the lack of automated
and distributed systems, with considerable computing power, to support the reasoning on a
huge quantity of knowledge, extracted by sensor data.
So, the thesis researches new approaches for distributed Context and Situation Awareness
and proposes to apply them in order to achieve some related research objectives such
as knowledge representation, semantic reasoning, pattern recognition and information retrieval.
The research work starts from the study and analysis of state of art in terms of
techniques, technologies, tools and systems to support Context/Situation Awareness. The
main aim is to develop a new contribution in this field by integrating techniques deriving
from the fields of Semantic Web, Soft Computing and Computational Intelligence. From
an architectural point of view, several frameworks are going to be defined according to the
multi-agent paradigm.
Furthermore, some preliminary experimental results have been obtained in some application
domains such as Airport Security, Traffic Management, Smart Grids and
Healthcare.
Finally, future challenges is going to the following directions: Semantic Modeling of
Fuzzy Control, Temporal Issues, Automatically Ontology Elicitation, Extension to other
Application Domains and More Experiments. [edited by author]XI n.s
Varieties of interaction: from User Experience to Neuroergonomics:On the occasion of the Human Factors and Ergonomics Society Europe Chapter Annual Meeting in Rome, Italy 2017
Proceedings of the HFES European Chapter conferenc
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